Scanning the issue

Network methods are by no means limited to lumped systems. Once the ports of a generalized physical structure are defined by use of a modal decomposition of signals, the structure can be analyzed using network techniques which extend beyond the domain of RLC systems and rational network functions. If the physical system is observed as a black box at its ports and various physical time-domain postu...
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The overall performance characteristics of ground-level millimeter-wave links are analyzed. Transmission reliability is examined on the basis of statistical data on pertinent meteorological variables and as a function of various link design parameters. Link systems operating under climatic conditions roughly characteristic of those prevailing along the mid-Atlantic coast of the United States are f...
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Consideration is given to the realization of maximally flat amplitude responses of overall fractional bandwidths ranging from 30 to 150 percent, using mutually coupled double-tuned networks as coupling elements. No restriction on the Q of the coupled circuits has been imposed and design curves for determining the network parameters for any value of primary Q are included. These have been computed ...
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By using Shannon's sampling formula, the problem of the detection of a deterministic signal in white Gaussian noise, by means of an energy-measuring device, reduces to the consideration of the sum of the squares of statistically independent Gaussian variates. When the signal is absent, the decision statistic has a central chi-square distribution with the number of degrees of freedom equal to twice...
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The small-signal theory of the parametric coupling of two waves in the presence of attenuation is summarized. The example chosen to illustrate the effects of losses on parametric coupling is two transmission lines coupled by a temporally and spatially varying capacitance. Included are analyses of contra- and co-flow parametric coupling, i.e., group velocities of the waves in the opposite and the s...
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As an application of high-field, high-current superconductors we sketch the design of a power transmission line to carry 100 GW (1011watts) of direct current over a distance of 1000 km. (It is interesting to note that the present peak power generating capacity of the United States is approximately 200 GW, or just twice the capacity of the proposed line.) Such a line, in contrast to one ...
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Beam-intensity modulation based on varying the power of the hydrogen RF-discharge was used in an automatic tuning system. Two hydrogen masers were tuned automatically and simultaneously. Their beat frequency was measured to have a long-term stability of 3 × 10-13.
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Two grounded, inverting amplifiers, interconnected by resistors and capacitors, can synthesize an open-circuit voltage gain equal to any ratio of real polynomials in the complex frequency variable. The amplifiers can have finite gains (greater than unity), finite input conductances, and finite output resistances.
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Scattering matrix problems requiring complex normalization can be converted to real normalization problems. This letter shows how this may be accomplished by defining a new port voltage applicable to a simple modification of the original network being considered.
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It is shown that a particular type of traditor, i.e., a three-port network element derived from the Lagrangian L = Aq1q2q3, where qkdenotes the charge driven through port number k, can be realized by idealization of a circuit comprising two Hall plates situated in the magnetic fields of two driving coils, and two gyrators.
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A relation is described which, when satisfied by a set of orthonormal functions, is sufficient to assure that the spectral coefficients of a system can be obtained in a simple way from the spectral coefficients of the input and output signals.
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The time dependence of the coherent emission wavelength shift of GaAs1-xPxlaser diodes during a flat-topped, 240 ns current pulse (20 ns rise time) was measured and found to agree reasonably well with calculations based on a simple thermal model of the diode which gives a square root of time dependence.
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Means of reducing undesired modes on axial-mode helical anteanas are presented. Using tapered feeds and tapered terminations, the radiation properties and impedance behavior of helical antennas may be substantially improved.
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An axial mode helix in a conical horn produces a circularly polarized pencil beam of low sidelobe level over a 2-to-1 bandwidth. The gain of the combination or "helicone" is four times that of a simple helix of the same length and the sidelobes are 15 to 20 dB lower.
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Sources of error in present methods of measuring circuit delay are described, along with a new technique which is particularly well suited to sub-nanosecond measurements. This technique measures the insertion delay of the circuit in a transmission system, has a time resolution of less than 10 picoseconds, and is directly calibrated in terms of length and the speed of light.
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The autocorrelation function for the output signal of a phase-modulated oscillator is derived directly, without the use of series expansions. The modulation characteristic of the oscillator contains a quadratic non-linearity and the modulating signal is assumed to be a stationary Gaussian process.
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A wideband electrically controllable resistive attenuator using a distributed MOS transistor is described. Bandwidth and attenuation for lumped and distributed structures are compared and a quality factor is defined. Some exmples of application for controlling the gain of amplifiers are also given.
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An anomalous shift in the gate threshold voltage of high-transconductance p-channel MOSFET's has been observed during exposure to space-like radiation of 2 × 1012electrons/cm2that is two and one half to three times its saturation value at 2 × 1014electrons/cm2and is five to seven times its pre-irradiation value.
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In this letter it is proven in a simple manner, without using results from electrical networks, that the basic loop matrix of a connected graph is unimodular. This result is established by using several properties of loop matrices in the theory of linear graphs and basic results from linear algebra.
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A proposed temperature sensor is described which consists of a pyroelectric material on the gate of an MOS transistor. Analysis of the device shows a sensitivity of 6.6 × 10-9°C is possible.
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A description is given of meteorological factors associated with a severe nocturnal signal strength depression on 4 GHz radio paths, over a coastal plain in South Australia. It is suggested that the fading was caused by a subrefractive layer, formed when a cold front moved slowly over a region where a radiation inversion existed.
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